Wyoming State Water Plan - Wind/Bighorn/Clarks Fork River Basins: Issues

Wind/Bighorn/Clarks Fork Rivers

Current Issues:

In 1977 the State of Wyoming filed suit in the Fifth Judicial District Court for the determination of water rights in the Big Horn River basin. Because of the complexity of this case, the Special Master for the litigation divided the adjudication into three phases. Phase I addressed the quantification of the Reserved Water Rights for the Wind River Indian Reservation. The Wyoming Supreme Court's decision concerning the tribal claims, as affirmed by the U.S. Supreme Court, awarded approximately 500,000 acre-feet of reserved water rights in Phase I. 250,000 acre-feet of this award was for "future" development of practicable irrigable acres with the Reservation. The extent of additional individual 1868 water rights, the "Walton" rights portion of Phase I, is currently being determined by the state district court.

Phase II of the suit dealt with non-Indian Federal Reserved Rights. In 1982, an interlocutory decree was entered by the court to quantify the water rights held by the Forest Service, Bureau of Land Management and other federal agencies within the Big Horn Basin. Revisions to the original interlocutory decree are continuing and a revised court decree is anticipated.

Phase III is the determination of the status of all uncancelled, unadjudicated permits (both surface water and groundwater) in the basin. On-the-ground inspections of the lands are continuing by the staff of the State Engineer's Office. After the completion of the inspections, reports are sent to the court regarding the status of the lands and their associated water right permits. Phase III will not be completed until the end of fiscal year 1999.

The waters of this basin are an important habitat of the Yellowstone cutthroat trout, and the Wyoming Game and Fish Department believes that protection of this species with instream flows is important.

Compact Allocations:

The Yellowstone River Compact among Wyoming, Montana and North Dakota has apportioned the flows of the Clarks Fork. The compact gives 60% to Wyoming and 40% to Montana, based on flow measured between the last diversion point on the Clarks Fork and Rock Creek. The flow of the Bighorn River is apportioned 80% to Wyoming and 20% to Montana. All valid water rights prior to January 1, 1950 are recognized by the Compact. The supplemental supplies necessary to bring a full supply to lands with a pre-1950 water right are also exempt from the percentage allocations.

Future Concerns:

Discussions are continuing with the Shoshone and Arapaho Tribes regarding the administration of the reserved water rights awarded for agricultural purposes and the Tribes' development of their "futures" award. The State would like to ensure that development of the "futures" award occurs in a manner that minimizes injury to junior water right holders. Rehabilitation projects to improve the distribution and efficiency of water delivery to tribal lands are also needed. Depending upon the outcome of the "Walton" rights hearings, the mixture of Indian and non-Indian water right holders with a 1868 priority date will be varied on Bureau of Indian Affairs developed lands and other areas across the Reservation. This "checkerboard" of 1868 and junior water rights creates significant water distribution and administration concerns for the state and Tribal water engineers.

A new water storage facility is being planned in the Bighorn Basin. Greybull Reservoir will be located in Roach Gulch off the main channel of the Greybull River and will provide additional irrigation supply to the Greybull Valley Irrigation District. The reservoir will be located downstream from the irrigation district's other storage in Upper and Lower Sunshine Reservoirs. The Water Development Commission is providing planning and construction funds.

The Seven Basins of the Water Plan
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